If NSW's low COVID-19 rate due to luck, as Dr Norman Swan says, why have lockdown at all?

http://www.matthaydenblog.com In an interview in mid 2020 Dr Norman Swan took issue with the claim made by ScoMo et al that NSW hasn't been hit anywhere as hard as Victoria by the dreaded 'rona because its response was "the gold standard". He said that the state was actually lucky. Well, if mere chance was such a huge factor in this outcome, why have any containment or elimination measures in place at all? What's the point of lockdown, contact tracing, masks and all the rest of it? Also he, like so many other go to "experts", has praised Victoria for its stringent response in the past. So, if it "did everything right" and continues to do so, why do the cases rise inexorably? Surely this is proof that the Andrews Government's jaw-droppingly draconian measures are simply not justified.